React CSS in JS

gistfile1.md

##Implementation issues

###How do we expose declaration blocks from at rules? CSSMediaRule instances could be exposed as flags through the content property of a pseudo element (applied to html/body?), and consumed through getComputedStyle. What about other forms?

###How do we deal with merging property shorthands? { background: red }, { background: url('...') yellow }

Unable to use pseudo classes/elements

The 'style' attribute can only contain property declarations

On pseudo classes - I think most of the functionality can be replaced with JS (since we are relying on JS anyway in the browser). And hover should not be used at all.

I agree that you can replicate user-interaction pseudo classes (:hover, :active and :focus) relatively easily. However, for every other category, we'd end up introducing a neutral element purely for the purpose of styling :(

hover should be considered a mandatory accessibility requirement in most projects, so it needs to be supported.